Combination cutting and grinding mill



0. N. GREDEL}.

COMBINATION CUTTING AND GRINDING MILL June 11, 1935.

Filed March 1-2, 1932 4 Sheets-Sheet 1 INVENTOR.

0/70 A! 6/50? MW ATTORNEY.

June 11, 1935.

o. N. GREDELL COMBINATION CUTTING AND GRINDING MILL- F'iled March 12. .1952 4 Sheets-Sheet 2 INVENTOR.

M. m 5 0 WM w A TTORNE Y.

June v11, 1935. O GREDELL COMBINATION CUTTING AND GRINDING MILL Filed March 12, 1952 4 Sheets-Sheet 5 .QMK u a A TTORNEY.-

June 11-, 1935. o. N. GREDELL 2,004,753.

' COMBINATION CUTTING AND GRINDING MILL Filed March 12, 1932 4 Sheets-Sheet 4 INVENTOR.

0 70 /ll G/edefl A TTORNE Y.

Patented June 11, 1935 PATENT I oFFiCE] COMBINATION CUTTING AND GRINDING MILL Otto N. Gredell, Kansas City, Mo., assignor to Standard Steel Works, North Kansas City, Mo.,

a corporation of Missouri Application March 12, 1932, Serial No. 598,407

4 Claims.

This invention relates to combination cutting and grinding mills andmore particularly to those of the rotary knife'and hammer type, and hasfor its principal object to provide a machine 55: which will economically reduce all classes of feeds such as the various grains, fodders, hay and ensilage, as well as other'similar materials, either separately or in combinationas in the preparation of mixed stock feeds.

to provide automatic feed of the material to the reduction chamber proportional to its rate of reduction :and delivery therefrom, to prevent spilling of small grain by the feeding mecha- 53 nism, to by-pass small grains and foreign objects so that they will not come into shearing contact withthe knives, and to provide for quick conversion from the grinding of grains to a set-up for cutting and elevating ensilage.

In accomplishing these and other objects of the invention, I have provided improved details of structure, the preferred. forms of which are illustrated in: the. accompanying drawings,

wherein: I

' Fig..1 is a perspective view of a combination cutting and grinding mill .and feeding mechanism constructed in accordance with my invention.'

Fig; 2 is an enlarged longitudinal sectional 30 view through the machine particularly illustrating the feeding mechanism for delivering material to thereduction chamber of the mill.

. I Fig. 3 is a plan view of a portion of the grinding mill and-the feeding mechanism associated 35' therewith. v

--lFig. 4 is a detail sectional view on the line 4-4, Fig. 2, particularly illustrating the hopper.

fordischarging small grains into the reduction chamber and the baffle for preventing reduced 40-- material from blowing back into the hopper.

Fig. 5 is a detail perspective view of the hopper for delivering small grains to the reduction chamber. 3

Fig. 6 is a side elevational view of the machine, a part of the reduction chamber housing being broken away to better illustrate the screen covering the outlet passage from the reduction chamber.

Fig. '7 is a detail view illustrating the grind- 1 ing mill after it has been converted for cutting ensilage. I

.Fig. 8=is a detail perspective view of the cutvoff gate assembly which controls the amount of small grain delivered by the conveyor mech- 55. anism.

Other important objects of the invention are,

Referring more in detail to the drawings: 4

I designates a grinder casing i'ncluding'vertical side plates 2 and 3 spacedapart by asubstantially circular band 4 to form a cylindrical reduction chamber 5. The ends 6 and 'I of the band terminate short of each other to provide an arcuate outlet 8 arranged to discharge material at the upper periphery ofthereduction chamber into an exhaust chamber 9. J

The exhaust chamber is defined by upwardly extending portions of the side plates and by spaced cross plates l and II having the width of the band 4. The plate In extends substantially vertically between the side plates at a point spaced outwardly from a vertical tangent to the circular band, and its lower end is bent inwardly at an angle to connect with the band andto form a flange I2 for seating on an angle member I3 extending across the outer face of the band adjacent the end I thereof. The angle member is spaced below the end of the band'to forma screen-engaging ledge I4 for ascreen I later described.

The other plate II has its lower end engaging the opposite end, but is spaced from its edge 6 to form a screen seat for cooperating with the ledge I4 of the band. The other end of the plate is inclined upwardly toward the plate In to form therewith a discharge neck I6 to connect a suitable discharge conduit (not shown).-

The band 4, including the plates Ill and II,

is clamped in position between the side plates. 2 and 3 by bolts I1, certain of the bolts extending through triangular shaped loops l8 that are Welded to said members, as best illustrated in Fig. 6.

the degree offineness of material discharged from the reduction chamber, which, of course, depends upon the nature of the material being ground and the purpose for which it is used.

The ends of the screenrest upon the ends of the band 4, while the side edges thereof extend through suitable slots in the side plates and are clamped by arcuate clamping plateslfl" which form the subject matter of a co-pendcooperate with the inner face of the band 4 and ing application, Serial No. 561,173, now ma-.

tured into a patent, No. 1,928,887.

Formed in the side plate 3 at the side opposite to the screen I5 and at a point intercepting the horizontal diameter of the reduction chamber is a substantially rectangular main inlet opening 2| through which roughage material is discharged into thereduction chamber, as later described. Also formed in the side plate 3 at a point spaced directly below the opening 2| is a substantially triangular-shaped auxiliary opening 22 through which small grains and foreign objects are bypassed into the reduction chamber. Fixed to the outer faces of the side plates 2 and 3 and extending thereacross are hori'-.

zontally positioned angle bars 23 and 24, respectively. The bar 24 extends across the plate 3 position across the-bottom edge of the inlet opening. 2| tov cooperate with rotating knives carried on a rotor 3.0..

The rotor 30 includes ardisk 3| having a central hub 32 through which a shaft 33 is extended to mount. the rotor within the reductiongchaniber, the ends of the shaft 33 being mountedin suitable bearings 34 and 35 secured to. the side plates 2 and 3, respectively.

.Theends, of ,the shaft 33 project through the bearings and the end adjacent the bearing 34 is provided with a pulley 36. through which power is applied to operate the rotor from a suitable prime ,mover, not shown, while the other end mounts. a worm gear 31 for operating the material feeding mechanism later described. i i

Extending from the face of the rotordisk adjacent the plate 3 are, pairs of radially spaced bosses 38 for mounting knives 39 adapted to cooperate with the shear bar 25 for cutting material delivered through the inlet opening 2|. with a plurality of hammer-like plates 40 which screen |5' to further reduce the material to the fineness where itwill pass through the screen. The hammer. blades 40' preferably include body portions having flat, forward faces 4| of suflicient width to extend substantially across the width of the reduction chamber and of suflicient length to retain the material in grinding contact with the inner periphery of the ChaIIb' ber.

The back faces of the hammer-like blades are provided with spaced ribs 42 terminating in ears 43, straddling the edgeof the disk and forming means by which the hammers are .pivotally mountedby bolts 44 extending through the ears and throughsuitable openings inthe disk. The

flat faces of the hammers also serve as fan blades 3at=opposite sides of, the inlet opening 2|. The,

The periphery of the rotor disk is provided.

outer ends of the angle bars are supported by vertical angle-shaped legs 48 and 49 having their lower ends engaging the ground while their upper ends are bolted to the ends of the angle bars and diverge outwardly to form inclined side boards 52 and 53 extending upwardly and outwardly along the vertical legs of the spaced angle members 48 and 41 to form, guides for the ma-- terial as it is delivered to the reduction chamber. The opposite ends of the side boards 52 and 53 are drawn inwardly at their forward ends to substantially thespacing of the bars 46 and 41,

,and are supported by vertical angle bar posts 54 and 55 attached to the spaced bars at a point spaced from the: grinder housing. The upper ends of the posts 54 and 55 are braced by a connecting cross member 56, while their lower ends, from the points where they attach to the angle members 46 and 41, incline toward the bottom edge of the plate 3 to connect therewith and form braces 51 for supporting theintermediate portions of said bars and. 41... Extendingupwardly from the angle bars 46 and 41 andconnecting the. terminalsof the side. boards,52, and 53--.with-.the side-plate 3..are spaced side board extensions 58 and 59 forming a. feed chamber fifitherebetween; Theends of the plates 58 and 59 opposite the posts 54' and 5.5 are flanged laterallyv and are secured-z tor-the side plate3. I x

Slidable between the side plates 53 and 5315 a: damper 6|. adaptedtopontrol. the; eflective air. inlet area of the inlet 2| to control-thevolume and velocity of the air.v admitted .therethrough, The damper 6| is slidably fixed to theside plate 3 by a bolt SIlpi-ojecting through. a. slot 32, formed in the upper portion thereof asillustrated in Figs. land 2. r Connecting the} angle bars and 4.1. adjacent their outer ends at a point in alignment with the posts 5.4. and 55 are :cross tie members 63 and 84, respectively, eachjincluding angle bars hav-i ing one-of their flanges.extendinghorizontally to provide supports for cooperating with: the in: wardly extendingfianges: of the members" 43 and 41 to support-a horizontal floor plate-65 fora conveyor 66;. in. r

The conveyor 66 includes a forwardly 'positioned shaft 61 supported 'inJbearing-platesr68 depending from the longitudinal angle barsv 46 and 41 at. a point spaced from the side plate}; of the; reduction chamber, and a complementary shaft 59- havingitsends' slidably supported in plates 10 located atthe opposite endsiof the angle bars, the respective shafts being provided with pairs of sprockets 1|r-and;1r2 located'thereonadjacent the side :boards 52. and-'53 for mounting chains 13 and 14; forming the sidesof an; endless.

raddle; e r The raddle preferably includes interlockedcross slats 15. connecting the chainsand spaced channel-shaped cleats, 16- positioned at: suitable intervals to eifect positive feed of material: to the: reduction chambenL The'upper run of the raddle operates over the floor, plater65 toward thefeed: chamber, while the lower'run returns under thetableas illustratedin. Flgc 2. v I

The raddle thus described is tensloned. between the sprockets to take up theslackthereinfby moving the shaftBQ-taand; firom the shaft Us This adjustment is accomplished by threadeddrawibo'lts 11 adjustably. mounted: in the depending flange *of the: angle 84. and having'ringshaped endswlB" for engaging over the ends. or

the shaft.

In order to provide a guide for the end of =the'conveyor 'raddle where it rounds about the -'sprockets"1-l I provide a. curved shoe T9 supported byjthe shaft by means of depending webs provided with bearing openings through which the shaft 1 6 9 'is extended. Theshoe member f9 includes a forwardly projecting shelf portion BI for supporting a cross plate 82 sli'dable 'below the end of *the plate 65 and above thetiemember-M', so 'that when the shaft 69 is adjusted to varythe tension of the ra'ddle, the plate "82 underlapping the floor plate prevents small grains "from dropping through the 'raddle,

As :previously pointed out, the delivery end or 'the raddle is'spaced'from the inlet-opening 21 to accommodate a stripping 'roller 83 for stripping the raddle of material that may tend to carry over with the -lower run "thereof, and to provide a passageway '84 through which small grain-s are-by-passedinto a h0pper*85 suspended "from the side members '46 and 41, as best illustratedin FigsfiZ and"6.

The'stripping or feed roller 83 includes a cylindricalbody 86 having a plurality'oi' rows of 'te'ethfll extending about itsperiphery to engage "the:roughagematerids, such'as hay and fodder -thatmay be delivered-to the reduction cylinder. "The "feeder *83'is keyed to a shaft-88 that is rotatably mounted in. the bearing plates 68 previously described.

'Bupported "and bridging the space between the feed roller 83 and the shear bar 25 is a 'plate 83 having teeth'8'l to extend between the teeth ST-ofthe roller toremove material that may tend"tolodge thereon.

*Swinginggly mounted inthe feed chamber above the feed :roll and the conveyor 66 is a 'secondary feed raddle 80 for forcing material into contact with thestrippingroller and through "the i inlet opening; as 'now described. The raddle *80- includes a pivot shaft *9! extending across the upper --rear edges of the sideboard extensionsan'd'having its ends rotatably mounted in bearings92 carried at the upper-ends of the posts 54 and-55.

'Pivotally mounted on the shaft '91 and 0D- erable between the sideboard'extensions is a raddle-frame 93 includingside bars 94 and-95 having their rear ends swingingly supported on the-shaftill, whiletheir'forward ends are nor- 'mally suspended 'from 5 the upper edge of the side -board extensions by links 96 and 91. The links 56 and -91 'are supported at their upper ends by a rod98'-having its ends normally resting -on -the *upper edge of the side boards to limit downwardly swinging movement of the secondary raddle to prevent contact thereof with the conveyor 66 previously described.

Fixedto'the-ends of the rod 98 are lever arms 99 and H10 having their ends projecting rearwardly along the side boards and pivotally =mounted -=in slots-I 01 that are formed in the fianges of the angle posts 54 and 55, as illustrated in'Fig. 1. The lever arms are-provided along their upper-edges -v/ith a series of notches I02 for engaging the hookedends lf03 of .ten-' 's-ion springs l-M that are connected at their lower ends withbrackets Hi5 carried by the-side members 46 and 41, as best illustrated in Fig. 1. "The'raddIe-BO also includes ashaft lilfi'rotatably mounted in the lower ends of the arms and 95. The shaft is-preferably slidable "in suitable slots in "the-ends oi the side bars by iadjusting' screws similar-to the adjusting" screws "46 and 41,

11, whereby it may be adjusted to and from "the shaft -9! 'to tensionthe raddle.

Supported at the lower-edges of "the bars B4 and 95 is a backing plate P0! over which the lower run of the'raddle 108 operates. The radable over pairs of sprockets 1-H and HTfixed'to and that'the material being fed by the primary i conveyor-must raise the -raddle-90 against tension of the springs fllt'to be forced through the inlet opening. The tension of the springs may be regulated *by moving the ends thereof "to any one of the notches which-varies the effective leverage on the arms, to apply pressure 'to'eth'e material being fed to the reduction chamber.

In order to .close'the space H4 which'is necessary between the side plate "3 of thereduction chamber and the end of the secondary raddle,

I provide a roller H5 having its ends 'fioatingly mounted in bracket armsl It that are welded to the suspension links QBand 91 at apoint above the raddle. The ends of'the bracketsll6 are provided with elongated slots 1 I 1 to a'ccommodate movement of the roller "and to 'form guide tracks for the roller 'trunnions H8. The

brackets "H6 are provided with notches 'H9 opening to the slots H 1 through which the trun-, nions may be inserted... 'The roller H5 is arranged to move in rolling contact with' the'control damper 6| so that as .the secondary 'raddle swings on its'pivotal-mounting'the opening'tbetween the end thereof and the reduction chamof the secondary raddle'from carrying back material and to serve as 'a bafiie for deflecting material that may be thrown "back "from the reductionchamber The hopper ,85 is ,best illustrated in Figs. 12,

" land 5, and includes a'sloping bottom ex"- tending from "the under side of the primary raddle to the lowermost edge oi the opening 22 "f or gravitating the grain discharged through 'tnepassage 84 into the reduction chamber; The

bottom 120 also includes a laterally inclinedportion IZl having its rear end extending along the inclined edge portion of the opening-"22, and -m'ounts a deflector for trapping material reduced in the grinding chamber.

The deflector E22 includes an inverted troughshaped portion I23 forming a ridge having a closed rear end I24 forming a pocket l-with the inclined walls 1-26 and I2! of the ballle; The

side wall I21 of the baffle preferably ezrteriutls to the delivery edgeof the hopper'in order to prevent the air blast from blowing small grain back into'the hopper. e a v "The hopper includes vertical side members are bolted to the longitudinal frame members The upwar'd'extensions I are also vprovided with guard plates :l3'l and 1'32 forg'uiding grainthat may tend *to passthrough the slotsthat are necessary to accommodate {the sprockets -12 from-dropping onto the lower 'run of the raddle and being carried 'back thereby! In order to drive the feed mechanism, the worm 3'i on the rotor shaft ismeshed with-a her will remain closed to preventtheiupperrun 5'28 and 112-9 having upward extensions 1:31] :that

,facing clutch teeth I48 and worm from driving connection with the rotor shaft when the rotor speed is reduced below a. certain RLP. M. to stop feed of material untilthe rotor again attains its normal working speed.

The specific construction of the clutch and governor form no part of the present invention,

but constitute sub ject matter of a separate application. V I A The shaft I35 is provided with a pair of sprockets I38 and I39 at opposite sides of the worm gear housing -I40,.the sprockets I38 and I39 being of differential diameter in order to furnish a plurality of speeds for driving a counters haft I4I which is rotatably mounted in bearings I42 carried by the brace portionsqof the posts 54 and 55. V

The 'countershaft MI is provided with sprockets I43 and I44Yaligning respectively with the sprockets I38 and I39, and driven by chains I45 and I46 operating over the respective sprockets. .The sprockets I43 and I44 are loosely mounted on the countershaft I4I but are adapted to be selectively connected therewith by asliding clutch collar I41 having oppositely I49 to engage clutch faces I50 and I5I on the respective sprockets. The clutchcollar is actuated by a shifting lever I52 pivoted adjacent the collar on a bracket arm I53 supported by the frame extension, as best illustrated in Figs. 2 and 6, the lower end of the shifting lever being provided with a yoke I54 engaging in a circumferential groove I55 of the collar. The opposite end of the arm projects rearwardly along the .side of the primary conveyor frame inv easy reach of the operator.

The opposite end of the countershaft is provided with a sprocket I56 for driving a chain I51 operating over a sprocket I58 on-the end of the secondary conveyor pivot shaft 9I, over a sprocket I59 on the end of the primary conveyor shaft 61, and over an idler tensioning sprocket I60. The idler sprocket is carried in a bracket I6I supported by the side plate 3 of the grinding mill. I

In order to drive the stripping roller 83, it is provided with a sprocket I62 which-is operated by a chain I63 running over a sprocket I64 mounted on the conveyor shaft 61 alongside of the sprocket I59. 7

It is thus apparent that the countershaft, through the sprockets I56, I58 and I59, and chain I51, drives the primary and secondary raddles'while the sprockets I62 and I64 operate able prime mover. to actuate the rotor 38 and the worm 3'I on the rotor shaft, which in turn operates the worm gear and the jack' shaft I35. The damper (H is positioned to regulate the air volume and the proper tension is applied to the 'a'oo pts secondary raddle 90 by movingthe hooked ends of thesprings I04 to the proper notch I62 in thelever arms 99 and I00. The clutchicontrol] lever I52 is then moved to engage either of the sprockets I43 or' I44 depending upon ijlie'coliveyor speed desired. The speed at which .the material can be fed is governed by the degree of dryness thereof, as well as the rate of. reduction and clearance through the screen. 7

Upon engagement of the clutch with either one of the sprockets, the countershaft I4 I".b'e'- gins'rotation to drive the chain' belt I51] to ac.- tuate the sprocket I58 on the secondary raddle shaft 9| and the sprocket I59 on the'r'nain'r'alddle shaft 61 to operate the respective raddles in a direction to feed the material toward the reduction chamber.

Rotation of the main conveyor sharfi'si effects rotation of the stripping cylinder through the chain I63 and sprockets I62 and, I64 on the shaft 61 and the shaft of the stripping cylf inder, respectively, rotating the stripping cylinder in an anti-clockwise; direction (Fig. 2) to prevent thefodder from following. thel'ow er' run of the raddle. The fodderis then fed in suitable quantities on the upper run. of the main raddle. Moving of the raddle causes the cleats I6 to engage the fodder and advance it toward the secondary raddle 90.. f I

The fodder, on being engaged by the raddle 90,.is pressed in-close contact with t he' upper run of the main raddle' and the stripping cylinder 83 which then draws the fodder fromthe raddles and feeds it through the inlet opening of the reduction chamber. On passage of the material under the secondary raddle .itwill swing the raddle on its pivot shaft 91 "an-amount proportionate to the tensionof the springs I04.

During the upward movement of the secondary raddle, the cylinder II5 rolling in contact with the side of the feeder' housing willniaintain the space II4 closed against the escape of fodder which may tend to blow back or be carried backwardly by the upper run of thesecondary raddle. As the'fodder passes the shear blade 25 it will be cut into shortlengths by the rotat ing knives 39 on the rotor. a l

Rotation of the rotor causes a stream of air to be drawn through the inlet openings to cooperate with the raddlesandstripping cylinder in feeding the material into the reduction chamher. The cut material, when caught in the swirling air created by the hammers is directed to the inner periphery of the band 4 by centrifugal force of the revolving mass, whereit is engaged by the hammers 4 0. and reduced "by grinding impact thereof against the screen until it is of sufficient fineness to pass therethrough aided by the blast of air discharged through the r exhaust passageway. 7

Should foreign matter, such as wire etc., be delivered onto the main raddle, it will drop of! the end thereof into the hopper 85 where'it will gravitate through the opening 22 intoith'e; reduction chamber, thereby by-passing the shearing point of the knives.39 and shear bar 25.

' Should it be desired to provide amixed feed.

including small grains and fodden the small grains may be delivered onto the mainconveyor along with the fodder, but. these grains; -on reaching the end of. the raddle will. drop through the passageway adjacent thestripping cylinder into the hopper 85, where they will gravitate through the opening 22 in the reduction chamher, while the fodder or roughage material will continue through'the opening: 2 I to be cut into small'pieces. r

"Due to the position of 3 the opening 22,-.some of'the reduced material may tend toblow back therethrough into the hopper --85,'-but'-this is prevented by the pocket-shaped deflector I22 which eifects'eddy currents that tend to return the material back into the reduction chamberl LAssuming that only :small grains'are to 'be delivered to the reduction chamber a cut-off gate assembly If65 isapplied in front of the secondary raddle, as illustrated in Figs. 2 and 8. The gate assembly includes a frame I66 supported across the conveyor and is provided with an opening I61 controlled by a gate I68 movable to and from the upper run of the raddle by a screw I68. It is thus apparent that the gate controls the amount of grain delivered thereunder for discharge through the opening 84 into the hopper 85, where it gravitates through the inlet opening 22.

When the machine is to be used for cutting ensilage, the hammers 40 are provided with extension plates I69 that are secured to the flat faces of the hammers by bolts I10 (Fig. 7) extending through suitable openings I'll provided in the hammers. The screen I5 is also removed and a short arcuate plate H2 is inserted in place thereof.

The plate I12 has one end resting against the ledge formed by the ends 6 of the band 4 with its sides supported in the arcuate slots of the side plates 2 and 3. Its opposite end terminates short of the plate I0 to provide a relatively narrow discharge opening I13 that is located tangentially of the reduction chamber adjacent the plate Ill. The lower end of the arcuate plate is provided with a channel-shaped groove I14 for securing the end of a plate I15 extending parallel with the plate ID to narrow the exhaust chamber. The open upper end of the exhaust chamber may be connected by a suitable distributing conduit (not shown) for elevating the ensilage to the top of a silo or the like. Otherwise the structure is identically the same as when the machine is used for grinding grains or roughage'material, the longer blades being required to obtain the proper velocity for the air Stream to elevate the ensilage.

Should the feed of material be such as to deliver larger quantities to the reduction chamber than the rotor can efliciently handle, its speed will be reduced, thereby causing the governor mechanism to disengage the worm with the rotor shaft, stopping operation of the feed raddles until the overloaded reduction chamber has been relieved, or until the passageways through the screen have been cleared, at which time the rotor will again pick up its speed to cause the governor mechanism to again effect operation of the conveyors to continue feed of material.

From the foregoing it is apparent that I have provided a feeding and grinding mechanism which is well adapted for all classes of feeds and ensilage, and that the hopper 85, together with the passageway at the end of the main raddle, forms a bypass for foreign objects that may be delivered with material to be reduced, thereby preventing damage to the cutting knives.

What I claim and desire to secure by Letters Patent is:

1. In a machine of the character described, a casing having substantially vertically spaced openings therein for admitting forage and grain respectively, a rotor in the housing for reducings, a conveyor supported in feeding relation with said openings for delivering; forage' material directly to the upper'opening, a hopper ing the .inaterial. delivered through "said -operbtoward said opening so that grain discharged 7 fromthe conveyor is delivered by the hopper in the direction of rotation of said rotor to .prevent rotation .of the rotor from interfering. with the delivery of the grain, and an inverted trough shaped baffle member fixed to the bottom of said hopper for stopping and diverting air blasts generated by said rotor to prevent their interference with the grain delivery into the casing.

2. In apparatus of the character described, including a housing, a primary conveyor for feeding material toward the housing, means supporting the delivery and of the primary conveyor in spaced relation with the housing, a stripper member rotatably mounted between the housing and the delivery end of the primary conveyor for removing material therefrom and discharging it into the housing, a secondary conveyor, a shaft for supporting the forward end of the secondary conveyor above the primary conveyor, lever arms mounted adjacent said shaft, a cross rod carried by the lever arms, strap members fixed to the cross rod, a shaft rotatably carried by the strap members for supporting the opposite end of the secondary conveyor above the stripper member whereby said secondary conveyor acts to move material from the primary conveyor across the stripper member, a cylinder carried by said straps and rollingly engaged with the housing to prevent material from being carried back by the secondary conveyor and yielding means connected with said lever arms for yieldingly retaining the secondary conveyor in contact with material fe across said stripper member.

3. A grinder for preparing mixed forage and grain feeds including a cylindrical housing forming a rotor chamber having upper forage and lower grain inlets in a side thereof and having an outlet for ground material in the periphery thereof, a screen covering the outlet, a rotor mounted in the chamber, knives on the rotor, a knife fixed in the housing at the for-' age inlet and cooperating with the rotor knives, a conveyor connected with the housing for delivering mixed forage and grain toward said inlets, means cooperating with the conveyor to deliver the forage through said forage inlet for initial reduction by the knives, hammer blades deflectorin the hopper for trapping and returning reduced materials that are blown from said grain inlet under fanning influence of the'rotor.

i. A grinder for preparing mixed forage and grain feeds including acylindrical housing forming a rotor chamber having upper forage'and lower grain inlets in a side thereof and having an outlet for ground material in the periphery thereof, ascreen covering the outlet, .a rotor a knife fixed to the housing atnthe forage inlet andcooperating with the rotor knives, a ,con- 'veyor connected with the housing for delivering mounted in the: chamber, 'knives on the rotor,

nected with the grain inlet for receiving grain from the conveyor and having an inclined'bottom portion sloping downwardly and laterally toward a vertical plane through the axis of the rotor for directing the graininto the'. rotor 1 chamber in the direction ofrotation of the rotor for direct reductionxby the hammers whereby the grain and initially reduced forage are ground and mixed in conformity to the rate of feed of said materials by the conveyor.

' OTTO N. GREDELL; 

